Mangroves: The Big Squeeze

January 12, 2011

Story By Cameron Cotner

Photos By Kevin Radley

I was jolted from my mid-morning coma by the sound of grinding metal. As we boarded the ferry on our way to Ca Mau, the southern tip of Vietnam, our bus driver, Duc, painted the cement with the rear bumper. It was only yesterday that I was finally able to catch a glimpse of rhizophora, the dominant species of mangroves resting on the coast of Bac Lieu as the sun began to sink into the South China Sea. Fully awake now, I’m anticipating a day amongst the mangroves that my itinerary promises.

Mangrove forests are in danger of being wiped out. Nearly synchronized, the ecological significance of mangrove forests was recognized as the fears and predictions of climate change surfaced. While the populous Vietnamese society presses toward the coast, the mangroves are squeezed by the encroaching sea.

Nearing the tip of the Ca Mau peninsula, we speed on a boat down a maze of river corridors. The area is laden with water, and there are no roads anymore. There they are: stream banks lined with mangroves. As we wind down the river racing past small towns and surrounded by prolific mangals, I begin to realize the severity of the problem.

Vietnam’s mangroves were threatened once before. During the Vietnam War, nearly 160,000 hectares were destroyed by dioxins used to deforest war zones. Initially expected to take 100 years to regrow, the mangroves have almost fully recovered.

Now there’s a new problem. Mangrove forests are being cleared for a new land use––agriculture and, particularly, aquaculture purposes. Days earlier, Dr. Duong Van Ni of Can Tho University explained that shrimp farms are popping up taking the place of forests everywhere as farmers recognize a higher income opportunity and Vietnam increases its production as the world’s 8th largest exporter of shrimp.

We reach the 42,000-hectare Mui Ca Mau National Park where I finally get to examine Rhizophora. It looks as if the tree might scurry off sitting atop its many spider-like roots. They are raised above water to more efficiently facilitate nutrient and gas exchange through lenticels––small holes in the bark. When they’re partially or fully submerged, they provide protection and breeding habitat for fish, oysters, shrimp, and other fauna.

It’s low tide now, and out of the corner of my eye I glance a mud–skipper tottering across the mud seeking refuge amongst Rhizophora roots digging into a thick layer of sediment. That is one of its unique abilities. Mangroves disrupt wave energy and allow sediment, which absorbs toxic heavy metals, to deposit. As I stare into the mud-skippers den, I ponder the contradiction. Mangroves that are relieving the environment of industrial pollutants are being cut down to make way for more industry.

Over lunch I listen to CTU professor Dr. Nguyen Van Be explain Vietnam’s current strategy to cope with rising sea levels. Vietnam is in the process of building a dyke that spans the countries entire southern coastline. Yesterday, I stood atop a dyke as I peered out at the ocean and the skinny belt of mangroves pressed between them. The fate of the mangroves is sealed as sea levels rise and the mangroves are locked out behind a dyke.

Posing beneath a statue marking the southern tip of Vietnam, 8° 37’ 30”; 104° 0’ 43”, it’s suddenly very surreal. I’m standing only a few meters away from where the Indian Ocean meets the South China Sea, under a landmark sure to be engulfed by both. With it, mangrove forests will perish behind a prison wall, cut off from society.